1. Field of the Invention
The invention relates to a storage shelf for goods or packaged goods, such as loaded pallets, for storing goods within the levels or planes of the shelves adjacent to one another as well as behind one another in the direction of the depth of the shelf. An operating device correlated with the storage shelf is configured to access the frontmost as well as at least one depth position of the respective shelf compartment arranged behind the frontmost position in order to place goods at or remove goods from these locations.
2. Description of the Related Art
Such storage shelves can be found primarily in large storage facilities comprising automated, computer-controlled pallets which are stored in and removed from the storage facility as needed. The standardized pallets are placed into and removed from a designated compartment of the shelf by means of specially constructed shelf operating devices. In this connection, the pallets are positioned on profiled members which extend in the depth direction of the shelf. When mounting the profiled members, care must be taken to provide a certain free space in the vertical direction into which the telescoping forks of the operating device can move for placing goods or for removing goods.
In order to achieve in large storage facilities an improved utilization of the available basic surface area, it is known, for example, from European patent 0 935 932 B1, to provide storage shelves with twice the storage depth. In this connection, the loaded pallets are positioned within one level of the shelf adjacent to one another as well as sequentially behind one another, i.e., in the direction of the shelf depth. The concept of storing more than two pallets behind one another in the direction of the shelf depth, however, fails because of static conditions of the shelf operating device. The employed telescoping forks which are laterally movable into the shelves must be able to withstand significant tilting and bending moments already in the case when only a first depth position for storing or removing is to be accessed. These forces are correspondingly higher in the case of storing or removing goods in a second depth position of the shelf compartment arranged behind the first (frontal) one. In order to be able to store goods in or remove goods from a third depth position behind the second depth position, the telescoping arms of the shelf operating device would have to be extremely heavy and voluminous in order to withstand the bending loads acting during use, in particular in the case of pallets with heavy loads. In practice, this concept is therefore avoided and pallets are stored, at most, in a double depth arrangements.
It is an object of the present invention to provide a storage shelf for goods or packaged goods with which by means of simple constructive means an enlargement of the storage depth and an improved utilization of the available basic surface area of a shelf storage facility can be obtained.
In accordance with the present invention, this is achieved in that for a storage shelf of the aforementioned kind the shelf compartment comprises, in addition to the frontmost and the at least one depth position arranged behind it, an additional rearmost depth position which cannot be accessed by the operating device, wherein within the shelf compartment a stationary support for the goods and a movable support for the goods are arranged, wherein the movable support for the goods is a carriage which is movable between a forward position and a rearward position by a length of a depth position, and wherein in the rearward position of the carriage those goods are stored which are in the rearmost depth position.
Such a storage shelf enables storing of goods or packaged goods, for example, in the form of pallets, at more than the double depth without straining the statics of the employed operating device. With the storage shelf according to the invention it is particularly possible to realize shelf compartments with three depth positions, i.e., a total of three pallets can be stored sequentially behind one another in the storage shelf. In this connection, when taking into account that on the other side of the aisle located in front of the storage shelf, in which aisle the operating device moves, a matching second storage shelf, is arranged, the operating device can store goods on either side of the aisle into a shelf compartment of triple depth in any position within the aisle, i.e., a total of six pallets can be stored in any position.
These advantages are achieved by dividing the supports for the goods of the shelf compartment. In each one of the shelf compartments a stationary support for goods and a movable support for goods are arranged, wherein the movable support for goods is a movable carriage. The carriage is movable between a forward position closer to the aisle and a rearward position, wherein the stroke of this movement matches a length of one depth position. The goods which are positioned in the rearmost depth position of the shelf compartment rest on the carriage when the carriage is in the rearward one of its two possible positions. The carriage, which preferably is shorter by one depth position than the total length of all depth positions of the storage compartment, is preferably provided at its forward end with a projection. This projection projects upwardly past the support surface of the carriage and serves for providing a longitudinal supporting action of the goods which are positioned in the frontmost position on the carriage.
According to a preferred embodiment, it is suggested that the carriage is provided with cutouts, extending in a longitudinal direction and being open toward a loading side of the shelf, allowing a free vertical penetration of the lifting fork of the operating device. These cutouts enable a free vertical penetration of the lifting or telescoping fork of the operating device when placing the goods onto the carriage or removing the goods from the carriage. A further embodiment is characterized by utilizing an operating device whose lifting fork is provided at its free ends with upwardly projecting projections. These projections are provided for partially engaging from behind the goods positioned on the lifting fork. The operating device can thus engage from behind the respective goods and can pull them forwardly within the shelf compartment. This movement is indirectly transmitted, i.e., by means of the goods which are engaged in this way, also onto the carriage so that as a result the lifting of the operating device is used to return the carriage from its rearmost position into its frontmost position.
Moreover, it is suggested that the carriage is provided with means for increasing the pushing resistance acting in the longitudinal direction between its upper side and the bottom side of the goods and that the pushing resistance generated in this way is greater than the moving resistance of the carriage. This configuration has the advantage that a pulling action or pushing action acting on the goods is transmitted on the carriage on which the goods rest. For moving the carriage it is no longer required to pull or push the carriage directly. Instead, this can be achieved indirectly by means of the goods positioned on the carriage.
Furthermore, it is suggested to configure the carriage to be moveable on rollers within the shelf compartment in order to keep the moving resistance of the carriage within the shelf compartment as minimal as possible. In order to enable a certain fixation of the carriage as soon as it is in the forward or rearward position, the carriage can be provided with means for increasing the rolling resistance. The obtained, position-dependent rolling resistance is smaller than the frictional or pushing resistance between the upper side of the carriage and the bottom side of the goods which are resting on the carriage.